fix strerror on mips: one error code is out of the 8-bit table range
fix strerror on mips: one error code is out of the 8-bit table range

if we ever encounter other targets where error codes don't fit in the
8-bit range, the table should probably just be bumped to 16-bit, but
for now I don't want to increase the table size on all archs just
because of a bug in the mips abi.

chardi/musl,chardi/musl,chardi/musl